Integrated air conditioning module for a bus

ABSTRACT

An air conditioning module having all the necessary components for conditioning air, is so sized and arranged that when placed in an internal compartment of a bus, has its respective openings register with an existing return air duct and a supply air duct on the bus. The compartments and modules are so arranged that they can be paired in back-to-back relationship, with one on each side of a longitudinal center line of the bus. Each of the modules has an intermediate partition dividing the module into an upper evaporator section and a lower condensing section. A mixer flap is placed in an intermediate position with respect to the partition such that its position may be selectively adjusted to thereby vary the amount of fresh air and return air that is passed through the condenser coil and evaporator coil, respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to the following pending applicationsbeing concurrently filed herewith and assigned to the assignee of thepresent invention: Title Our Docket No.: Modular Rooftop Air Conditionerfor a Bus 210_546 Modular Bus Air Conditioning System 210_545 Supply AirBlower Design in Bus Air Conditioning 210_549 Units Bus RooftopCondenser Fan 210_550 Method and Apparatus for Refreshing Air in a210_548 Bustop Air Conditioner Coil Housing Design for a Bus AirConditioning 210_547 Unit Integrated Air Conditioning Module for a Bus210_558 Fresh Air Intake Filter and Multi Function Grill 210_554Integrated Air Conditioning Module for a Bus 210_557 Modular AirConditioner for a Bus 210_561 Modular Air Conditioner for a Bus Rooftop210_562 Evaporator Section for a Modular Bus Air Conditioner 210_564Wide Evaporator Section for a Modular Bus Air 210_565 ConditionerCondensate Pump for Rooftop Air Conditioning Unit 210_568 CondensateRemoval System Rooftop Air 210_551 Conditioning Modular Rooftop UnitSupply Air Ducting 210_577 Arrangement Configuration for Modular BusRooftop Air 210_595 Conditioning System Unibody Modular Bus AirConditioner 210_596

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to air conditioning systems and,more particularly, to an air conditioning system which is integratedinto the internal structure of a bus.

[0003] The conventional integrated bus air conditioning systems containa condenser mounted in a luggage compartment and an evaporator mountedin the luggage compartment or in a separate compartment between thepassenger compartment floor and the luggage compartment underneath thefloor. The evaporator takes in the return air through a central returnair duct mounted under the floor of the passenger compartment and blowsthe conditioned supply air into a side wall supply air duct. Thecondenser, which, is interconnected to the evaporator by a refrigeranttube, operates to condense the refrigerant in the circuit by way of theoutside air that is brought in from and eventually discharged to theambient air.

[0004] As part of the refrigeration circuit which is fluidlyinterconnected by tubing to both the evaporator and the condenser, anopen drive reciprocating compressor is generally directly driven by abelt drive from the bus engine, such that the speed of the compressor isdependent on the speed of the drive engine. Accordingly, when the bus isat idle speed, for example, the capacity of the air conditioning systemis substantially reduced. Further, the refrigeration connections betweenthe compressor and the air conditioning system is generally expensive toinstall, difficult to service, and somewhat unreliable because ofpossible refrigeration leaks and the need to maintain a compressor shaftseal.

[0005] Also typical of such a bus air conditioning system is the use ofexisting DC power to power the evaporator and condenser blower motors.Because of relatively low brush life for such motors, reliability andexpense can also be a problem.

[0006] It is therefore an object of the present invention to provide animproved integrated air conditioning system for a bus.

[0007] Another object of the present invention is the provision for anintegrated air conditioning system that does not occupy a significantportion of a luggage compartment on a bus.

[0008] Yet another object of the present invention is the provision in abus for an air conditioning system whose performance is notsignificantly affected by the engine speed of a bus.

[0009] Yet another object of the present invention is an integrated busair conditioning system which is economical to install and reliable inuse.

[0010] Yet another object of the present invention is an integrated busair conditioning system that is accessible and easy to service.

[0011] Still another object of the present invention is an integratedair conditioning system for a bus which is economical to manufacture andeffective in use.

[0012] These objects and other features and advantages become morereadily apparent upon reference to the following descriptions when takenin conjunction with the appended drawings.

SUMMARY OF THE INVENTION

[0013] Briefly, in accordance with one aspect of the invention, aplurality of modules are placed under the floor of a passengercompartment of a bus, with each module having a complete airconditioning system which can be controlled independently of the speedof the engine.

[0014] By yet another aspect of the invention, each module has aninvertor/controller which is interconnected to receive power for agenerator and provide controlled AC power to the drive motors of acompressor and the condenser and evaporator blowers.

[0015] By yet another aspect of the invention, a plurality of compactmodules are slidably installed into or near a luggage compartment of abus so as to facilitate easy access for servicing the units.

[0016] In accordance with another aspect of the invention, the modulesare so designed that, when installed in their positions on the bus,their supply air outlet opening and return air inlet openings registerwith the existing supply air duct and return air duct on the bus.

[0017] In the drawings as hereinafter described, a preferred embodimentis depicted; however various other modifications and alternateconstructions can be made thereto without departing from the true spritand scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a perspective view of the modules of the presentinvention as installed in a bus.

[0019]FIG. 2 is a perspective view of a module in accordance with thepresent invention.

[0020]FIG. 3 is a cutaway perspective view thereof.

[0021]FIG. 4 is a schematic illustration of the electrical powerconnections on the module.

[0022]FIG. 5 shows the air flow connections between the module and theexisting ducts on the bus.

[0023]FIG. 6 is an expanded view of a portion thereof.

[0024]FIG. 7a-7 c show cutaway perspective views of the modules with theair flow patterns for different positions of the mixing flap.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0025] Referring now to FIG. 1, the inventive modules are shown at 11 asinstalled in a typical passenger bus having an existing side wall ductsystem 12 and an existing return air duct 13, both extendinglongitudinally on the bus. The side wall duct system is located withinthe side walls and communicates with the passenger compartment by way ofa plurality of openings. The return air duct 13 is located along thelongitudinal center line of the bus, near or just under the flooring orseats, and fluidly communicates with the passenger compartment by way ofa number of openings.

[0026] As will be seen, the modules 14 are located below the floor ofthe passenger compartment and above the luggage compartments 16 and arepreferably slidably installed to allow for easy access to accommodateservicing. They are relatively shallow in height and therefore occupy arelatively small space. They are paired, in back-to-back relationship,with the longitudinal position thereof being adjustable to meet theneeds of the individual bus application. The manner in which theyinterface with the existing side wall ducts 12 and the return air duct13 will be described hereinafter.

[0027] The construction and components of the module 14 can be seen inFIGS. 2 and 3 wherein a housing 17 includes a lower wall 18, an upperwall 19, an inner end wall 21 and an outer end wall 22. An intermediatepartition 23 divides the internal space between a condenser section 24in the lower portion of the housing and an evaporator section 26 in anupper portion thereof. Within the condenser section 24 is a condensercoil 27 and a condenser fan 28. The condenser fan 28 is of the draw-thrutype which functions to draw outdoor air into a condenser air intakeopening 31, pass through the condenser 27 and flow out of the housing byway of a condenser fan discharge opening 32 to the atmosphere.

[0028] Within the evaporator section 26 there is disposed an evaporatorcoil 33 and a evaporator fan 34 driven by an evaporator fan motor 36.The evaporator fan 34 is also the draw-thru type which acts to draw airinto the evaporator air intake opening 37, through the evaporator 33 andout a supply air outlet opening 38. Both the condenser fan 28 and theevaporator fan 34 are of the transverse type as shown and preferablyhave forward swept blades.

[0029] Near the longitudinal mid point of the module, the intermediatepartition 23 is made discontinuous and a fresh/return/exhaust air flap39 is hindgely mounted therein so as to selectively mix the variousflows of air as described hereinabove such that portions of those airstreams are diverted to other flow streams within the module as will bemore fully described hereinafter.

[0030] Also disposed within the housing 17 is a refrigeration circuit asshown in FIG. 4 to include a compressor 41 driven by an electric motor45 and with its discharge being fluidly connected to the condenser 27,which in turn is fluidly connected to an expansion valve 40 whichdischarges to the evaporator 33, which in turn is fluidly connected tothe compressor intake to complete the circuit. This closed circularrefrigeration system operates in a conventional manner to circulaterefrigerant which, by the various changes of state, provides for coolingof air at the evaporator 33 and the condensing of the refrigerant as itpasses through the condenser coil 27. An inverter 42 is also providedwithin the module for the purpose of providing power to the variouscomponents within the module.

[0031] The providing of power to the module occurs by way of thecircuitry as shown in FIG. 4 wherein the bus motor or engine 43 drives agenerator 44 which in turn feeds electrical power to theinverter/controller 42. Controlled power is then provided by theinverter/controller 42 to the individual motors 29, 45 and 36 as shown,with the controller responding to control sensors 46 to discreetlycontrol the speed of the respective motors. Each of the modules mountedin the bus have a similar invertor and control apparatus that is fed bythe generator to provide AC power to its various drive motors.

[0032] Referring now to FIGS. 5 and 6, there is shown the manner inwhich the individual modules are mounted within the bus so as tointerface with the existing side wall duct system 12 and return air ductsystem 13. In essence, the individual modules are identical and aresized and so arranged that when inserted into the opening under thefloor of the bus, the evaporator air intake opening 37 registers with anopening in the existing return air duct 13, and the supply air outletopening 38 registers with the opening in the existing side wall ductsystem 12 as shown. In addition, the condenser air intake opening 31 isdisposed near the outer side of the bus wherein fresh air can be takenin from outside.

[0033] In conventional integrated bus air conditioning systems, whereinthe condenser is located in a luggage compartment, there is a passagefrom the luggage compartment for providing fluid communication from thecondenser discharge opening to the outside. Accordingly, there is noexisting condenser outlet duct that will suffice for use with thepresent modules. Thus, this component must be added as shown at 47 inFIGS. 5 and 6. Here, a single condenser air outlet duct 47 communicatesat its upper portion with each of the identical modules on either sideof the center line of the bus, and acts to conduct the flow of air fromthe condenser fan discharge opening 32 of each to a discharge opening 48at the lower end of the condenser air outlet duct 47 as shown.

[0034] Referring now to FIG. 7a-7 c, the fresh air flap 39 is shown invarious positions for selectively directing the flow of air within boththe condenser section 24 and evaporator section 26 and for mixing theflows within the two sections.

[0035] In FIG. 7a, the fresh air flap is in a horizontal position suchthat it simply forms a continuation of the intermediate partition 23.When in this position, all of the return air passes through theevaporator section 26 and through the evaporator coil 33 to bedischarged out the supply air outlet duct 38. Similarly, all of thefresh air from the outside passes into the condenser air intake opening31, passes through the condenser coil 27, and is discharged from thecondenser fan discharge opening 32.

[0036] In FIG. 7b, the fresh air flap 39 is in an intermediate positionwherein a portion of the return air is diverted from the evaporatorsection 26 and passes downwardly to enter the stream of air passingthrough the condenser coil 27 and out the condenser fan dischargeopening 32. At the same time, a portion of the fresh air is divertedfrom the condenser section 24 to pass upwardly into the evaporatorsection 26, through the evaporator coil 33 and out the supply air outletopening 38. In this way a portion of the return air is dischargedoutside and is replenished with fresh air from outside which is thencooled and then supplied to the supply air ducts.

[0037] In FIG. 7c, the fresh air flap 39 is placed in the verticalposition wherein it completely blocks the flow of air flowing throughboth the condenser section 24 and evaporator section 26. When in thisposition all of the return air entering the evaporator air intakeopening 37 passes through the condenser coil 27 and is discharged outthe condenser fan discharge opening 32, and all of the fresh air passesfrom the condenser section 24 to the evaporator section 26, through theevaporator coil 33 and out the supply outlet air opening 38.

[0038] It should, of course, be understood that the fresh air flap 39can be placed in any other intermediate position not shown in order toobtain the desired mixtures that will meet the needs of the particularbus application, while at the same time taking into account theenvironmental conditions outside.

[0039] While this invention has been described with reference to theparticular structure disclosed herein it should be understood that it isnot confined to the details set forth in this application, but is ratherintended to cover any modifications and changes as may come within thescope of the following claims:

1. An air conditioning module for installation in an upper portion of aninternal baggage compartment of a bus having a return air duct and asupply air duct for respectively conducting air to be cooled from, andconditioned air to, a passenger compartment, comprising: an evaporatorcoil and a condenser coil interconnected with a compressor and anexpansion valve to conduct the flow of refrigerant in an operativeclosed circuit within the module; a condenser fan for conducting theflow of air from a condenser air intake opening in said module, throughsaid condenser, and out a condenser discharge opening in said module;and an evaporator coil fan for conducting the flow of air from anevaporator air intake opening in said module, through said evaporatorcoil, and out a supply air outlet of said module; wherein said supplyair outlet and said evaporator air intake openings are so situated thatwhen the module is installed in the internal baggage compartment, saidsupply air outlet is positioned adjacent the supply air duct and saidevaporator air intake opening is positioned adjacent the return airduct.
 2. A module as set forth in claim 1 wherein said module is sosituated in the air conditioning compartment that said condenser airintake opening is adjacent an outer side of the bus and said evaporatorair intake opening is adjacent a longitudinal center line of the bus. 3.A module for installation in an air conditioning compartment of a bushaving a return air duct and a supply air duct for respectivelyconducting air to be cooled from, and conditioned air to, a passengercompartment, comprising: an evaporator coil and a condenser coilinterconnected with a compressor and an expansion valve to conduct theflow of refrigerant in an operative closed circuit within the module; acondenser fan for conducting the flow of air from a condenser air intakeopening in said module, through said condenser, and out a condenserdischarge opening in said module; and an evaporator coil fan forconducting the flow of air from an evaporator air intake opening in saidmodule, through said evaporator coil, and out a supply air outlet ofsaid module; wherein said supply air outlet and said evaporator airintake openings are so situated that when the module is installed in theair conditioning compartment, said supply air outlet is positionedadjacent the supply air duct and said evaporator air intake opening ispositioned adjacent the return air duct wherein said air conditioningcompartment includes a condenser air outlet duct for conducting the flowof air from said condenser discharge opening of the module.
 4. A moduleas set forth in claim 3 wherein said condenser air outlet duct extendsdownwardly from said module.
 5. A module for installation in an airconditioning compartment of a bus having a return air duct and a supplyair duct for respectively conducting air to be cooled from, andconditioned air to, a passenger compartment, comprising: an evaporatorcoil and a condenser coil interconnected with a compressor and anexpansion valve to conduct the flow of refrigerant in an operativeclosed circuit within the module; a condenser fan for conducting theflow of air from a condenser air intake opening in said module, throughsaid condenser, and out a condenser discharge opening in said module;and an evaporator coil fan for conducting the flow of air from anevaporator air intake opening in said module, through said evaporatorcoil, and out a supply air outlet of said module; wherein said supplyair outlet and said evaporator air intake openings are so situated thatwhen the module is installed in the air conditioning compartment, saidsupply air outlet is positioned adjacent the supply air duct and saidevaporator air intake opening is positioned adjacent the return air ductwherein said module includes a mixing flap disposed in the flow path ofthe fresh air entering said condenser air intake opening, said flapbeing adjustable to selectively vary an amount of fresh air that ispassed to said evaporator coil.
 6. A module as set forth in claim 5wherein said flap simultaneously varies the amount of fresh air thatpasses to the condenser coil.
 7. A module as set forth in claim 6wherein the amount of fresh air passing to said evaporator coil and saidcondenser coil is inversely proportional.
 8. (Cancelled)
 9. An airconditioning module for installation in an upper portion of an internalbaggage compartment of a bus having a return air duct and a supply airduct for respectively conducting air to be cooled from, and conditionedair to, a passenger compartment, comprising: an evaporator coil and acondenser coil interconnected with a compressor and an expansion valveto conduct the flow of refrigerant in an operative closed circuit withinthe module; a condenser fan for conducting the flow of air from acondenser air intake opening in said module, through said condenser, andout a condenser discharge opening in said module; and an evaporator coilfan for conducting the flow of air from an evaporator air intake openingin said module, through said evaporator coil, and out a supply airoutlet of said module; wherein said supply air outlet and saidevaporator air intake openings are so situated that when the module isinstalled in the internal baggage compartment, said supply air outlet ispositioned adjacent the supply air duct and said evaporator air intakeopening is positioned adjacent the return air duct wherein said moduleincludes a mixing flap disposed in the flow path of the return airentering said evaporator air intake opening, said flap being adjustableto selectively vary an amount of return air that is passed to saidevaporator coil wherein said flap simultaneously varies the amount ofreturn air that is passed to the condenser coil.
 10. A module as setforth in claim 9 wherein the amount of return air that passes to theevaporator coil and to the condenser coil is inversely proportional. 11.A module as set forth in claim 1 wherein said module includes acompressor.
 12. A module as set forth in claim 1 wherein said moduleincludes an inverter for providing AC power to various motors in themodule.
 13. A module as set forth in claim 1 wherein said airconditioning compartment is under the floor of said passengercompartment.
 14. A module as set forth in claim 1 wherein said returnair duct is located substantially on a longitudinal centerline of saidbus.
 15. A module as set forth in claim 1 wherein said supply air ductis located in an outer side of said bus.
 16. A module as set forth inclaim 1 wherein said condenser fan is a transverse fan.
 17. A module asset forth in claim 1 wherein said evaporator fan is a transverse fan.18. An air conditioning module for placement in an internal compartmentof a bus having a return air duct and a supply air duct fluidlycommunicating with said internal compartment, comprising: a housingsized to fit into the internal compartment; a longitudinally extendingdivider wall for dividing said housing into an evaporator section and acondenser section; an evaporator coil disposed in said evaporatorsection and having an associated evaporator fan for causing air to flowthrough said evaporator coil and out a supply air outlet opening of themodule to the supply air duct; a condenser coil disposed in saidcondenser section and having an associated condenser fan for causing airto flow through said condenser coil and out a condenser dischargeopening of the module; and a mixing flap disposed in the module andbeing adjustable to vary an amount of return air flow passing from thereturn air duct into the evaporator section and through said evaporatorcoil.
 19. An air conditioning module as set forth in claim 18 whereinsaid mixing flap simultaneously adjusts the amount of return air flowthat passes from the return air duct into the evaporator section, intosaid condenser section and through said condenser coil.
 20. An airconditioning module as set forth in claim 19 wherein the volume of saidreturn air flowing to said evaporator section and said condenser sectionare inversely proportional.
 21. An air conditioning module as set forthin claim 18 wherein said mixing flap also simultaneously adjustablyvaries an amount of fresh air that enters a condensate air intakeopening in the module, passes through said condenser section, passesthrough said condenser and out said condenser discharge opening.
 22. Anair conditioning module as set forth in claim 21 wherein said mixingvalve simultaneously adjusts the volume of fresh air that passes fromthe condenser section into the evaporator section, through theevaporator coil and to the supply air duct.
 23. An air conditioningmodule as set forth in claim 18 wherein said longitudinally extendingdivider divides said housing into an upper and a lower section.
 24. Anair conditioning module as set forth in claim 18 wherein said evaporatorfan is of the transverse type.
 25. An air conditioning module as setforth in claim 18 wherein said evaporator fan is located downstream ofsaid evaporator coil.
 26. An air conditioning module as set forth inclaim 18 wherein said internal compartment includes a condenser airoutlet duct and further wherein said condenser discharge opening fluidlycommunicates therewith.